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In this study, Fe nanowires coated with SiO2 nanotubes have been synthesized by electrodeposition method using anodic alumina oxide template. Before growing Fe nanowires, 6-8 nm thick SiO2 nanotubes are grown inside the template using a "surface sol-gel" technique. The nanotube structures were characterized by field emission scanning electron microscopy and energy dispersive x-ray spectroscopy. Magnetic properties of the SiO2 insulated Fe nanowires inside the membrane are characterized by superconducting quantum interference device. Coercivities of around 120 Oe with field parallel to the nanowire axis and 240 Oe with field perpendicular the nanowire axis are observed at room temperature. These values are comparable to Fe nanowires without insulating layer in membrane. The magnetic hysteresis loop suggests that the SiO2 insulated nanowires have uniaxial magnetic anisotropy with the easy axis magnetization direction along the nanowire arrays due to their large shape anisotropy. [ABSTRACT FROM AUTHOR]

We demonstrate spiral inductors with continuous Permalloy ring structure at 100-\mu\m scale, which achieve enhancements of sixfold in inductance and threefold in quality factor at frequencies as high as 200 MHz. The roll-off frequency is due to the eddy current loss in the conductive magnetic material. To reduce such loss and tune the permeability, the Permalloy film is laminated and split into bars. The dependence of the inductance and quality factor on permeability is further investigated. Different types of spiral inductors were fabricated with magnetic rings, helping shed light on optimization strategy. [ABSTRACT FROM AUTHOR]